Not sure how much Plastishroom farmspace you need? Trust me, you're not the only one.
Production times for plastishrooms are weird, so let's find out what the deal is.
Plastishroom Farms can only be built down in the Marshy Ruins.
This is the second layer of the mine which is unlocked after you repair the second mineshaft in Dusty Caverns.
In Marshy Ruins, areas of fertile soil appear. Usually in patches of 15 to 30 tiles, this fertile soil is the only place where you can build Plastishroom Farms.
Fertile soil in Marshy Ruins is needed to grow Plastishrooms in SteamWorld Build
Actually, the Growth Cycle (production time) of wild plastishrooms is a constant. It is always 90 seconds.
If you select a farm, you will see a timer. The timer will loop constantly, count down to 0 and then start again at 90.
If you have multiple plastishroom farms in the Marshy Ruins, they will all have their own separate growth cycle.
A plastishroom farm doesn't have any items to improve the growth cycle. The growth cycle is also not influenced by the size of the farm.
However: the size of a plastishroom farm does matter!
Even though it doesn't impact the growth cycle, it does change the amount of platishrooms that grow and can be stored in the farm.
For instance: a 9 square plastishroom farm will produce 1 plastishroom every 90 seconds. But only if there is room to grow one. Which there isn't a lot of, as a farm of 9 spaces can only hold 1 plastishroom.
The plastishroom farm growth cycle in SteamWorld Build is a constant process running for 90 seconds.
If you add another square, the farm can hold 2 plastishrooms. Refer to the table down below for the farm size and growth capacity.
At the start of a growth cycle, the farm will determine whether there is enough space available to grow a new shroom. If not, the entire cycle will be wasted.
To harvest plastishrooms, you will need Prospectors. The Prospectors will make their way to the farm as soon as a ripe plastishroom is ready to be harvested. They'll bash the shroom with their pickaxe (very Minecrafty) and then carry the harvested plastishrooms to the elevator.
The yield of plastic from plastishrooms is actually 2 to 1. For each plastishroom harvested by a prospector, 2 plastishrooms will be added to your inventory.
As the farm will not grow new plastishrooms when a free spot is not available at the start of a growth cycle, it's important that prospectors are close and available to harvest at all times. Missing the deadline isn't a disaster, but it will affect your production rate.
Refer to this table to know how much plastishrooms can grow on a plastishroom farm of which size.
| Farm size (squares) | Growable Plastishroom | Plastishroom yield |
| 9 | 1 | 2 |
| 10 | 2 | 4 |
| 12 | 3 | 6 |
| 17 | 4 | 8 |
| 27 | 5 | 10 |
